1. Field of the Invention
The invention relates to an adhesive and binder for dermal and transdermal therapy systems.
2. Discussion of the Background
Adhesives and binders for pharmaceutical purposes, which are based on (meth)acrylate polymers with basic groups, in combination with plasticizers and with organic acids, are basically known.
A fundamental problem in pharmaceutical adhesives and binders is water vapor permeability. If this is not sufficient, the tolerance on the skin is impaired. In addition, there is the risk that the preparations, e.g. skin adhesive bandages, will dry up too quickly, which has a detrimental effect on the controlled release of the active substance.
Another criterion is so-called cold flow. Cold flow of an adhesive is understood to be the lack of adhesion when a force acts parallel to the adhesive surface. On the human skin, an overly high cold flow means that the adhesive bandage migrates while worn, and leaves dark edges or develops wrinkles. This is particularly disadvantageous for adhesive layers which contain active substances in transdermal therapy systems, because the absorption of the active substance by the body is influenced in an uncontrollable manner.
EP-B 415 055 relates to water-soluble pressure-sensitive skin adhesives. These consist of the salt of a non-cross-linked copolymer of a monoethylene-unsaturated, radically polymerizable monomer which contains amino groups and at least one alkyl ester of acrylic and/or methacrylic acid. The formulation is characterized in hat it is the salt of at least one higher organic carboxylic acid with 8-20 carbon atoms or a mixture of such a higher carboxylic acid with up to 30 mole % (the anionic equivalent) of medium carboxylic acids, and contains a monomer having amino groups, in the range of 30-80 weight % by weight of the copolymer, and is soluble in water in the salt form.
U.S. Pat. No. 3,321,451 describes skin adhesives that can be washed off, based on (meth)acrylate copolymers that contain amino groups, where the amino groups are partly present as the salt of an acid anion.
EP-A 164 669 describes a method for coating forms of medication by means of (meth)acrylate copolymers that contain monomers with tertiary amino groups, where these can be converted to the salt form by means of mineral acids or organic acids, such as acetic acid or citric acid, for example. The coatings are desirably as non-sticky as possible, in order to keep the coated forms of medication from sticking to each other.
EP-A 354 364 describes the use of copolymers that contain amino groups in an aqueous formation as adhesives. The amino groups are partly neutralized by acids such as fumaric acid or acetic acid, for example.
EP-A 315 218 describes pharmaceutical compositions for transdermal systemic administration of pharmacological substances, characterized in that the pharmacological substances are contained in a reservoir which contains a polyacrylate polymer with cationic properties. Additives such as plasticizers or surfactants can be present in amounts up to 50 weight %. The pharmaceutical compositions can be additionally provided with an adhesive layer, in order to achieve good adhesion on the skin.
EP-A 617 972 describes dermal therapeutical systems in layer form having a delayed release of active substance, which consists of mixtures of poly(meth)acrylates and which are produced from a melt. Here, one poly(meth)acrylate component contains functional groups, while another poly(meth)acrylate component does not contain, or contains only an insignificant amount of functional groups, and essentially regulates the flow behavior of the polymer adhesive layer.